Isocitrate dehydrogeses catalyze the oxidative decarboxylation of isocitrate to 2-oxoglutarate. These enzymes belong to two distinct subclasses, one of which utilizes D(+) as the electron acceptor and the other DP(+). Five isocitrate dehydrogeses have been reported: three D(+)-dependent isocitrate dehydrogeses, which localize to the mitochondrial matrix, and two DP(+)-dependent isocitrate dehydrogeses, one of which is mitochondrial and the other predomintly cytosolic. Each DP(+)-dependent isozyme is a homodimer. The protein encoded by this gene is the DP(+)-dependent isocitrate dehydrogese found in the cytoplasm and peroxisomes. It contains the PTS-1 peroxisomal targeting sigl sequence. The presence of this enzyme in peroxisomes suggests roles in the regeneration of DPH for intraperoxisomal reductions, such as the conversion of 2, 4-dienoyl-CoAs to 3-enoyl-CoAs, as well as in peroxisomal reactions that consume 2-oxoglutarate, mely the alpha-hydroxylation of phytanic acid. The cytoplasmic enzyme serves a significant role in cytoplasmic DPH production.